1. Technical Field
The present invention relates to an actuator drive system, an optical module, and an electronic apparatus.
2. Related Art
There is a known wavelength selective light reception device (wavelength tunable interference filter) including a pair of substrates facing each other, reflection films disposed on the respective substrates and facing each other, and electrodes (actuator) disposed on the respective substrates and facing each other (JP-A-2-257676, for example).
In an optical module including the wavelength tunable interference filter described in JP-A-2-257676 and a voltage controller that applies a drive voltage between the electrodes described above, which face each other, an electrostatic attractive force produced in the space between the electrodes in accordance with the drive voltage applied to the actuator changes the distance between the substrates and hence changes the dimension of a gap created between the reflection films, whereby light of a wavelength according to the dimension of the gap is selectively extracted.
In the wavelength tunable interference filter described in JP-A-2-257676, to precisely set the dimension of the gap corresponding to light of a target wavelength, it is necessary to adjust the drive voltage applied to the actuator in high resolution.
An example of the voltage controller that adjusts the drive voltage applied to the actuator in high resolution inputs a digital signal outputted from a microcomputer or any other digital control device to a drive voltage signal generation device (such as digital to analog converter (DAC) and voltage controlled pulse width modulator (PWM)) and applies an outputted drive voltage signal (drive voltage) to the actuator.
The voltage controller described above can adjust the drive voltage at higher resolution and hence change the displacement amount of the actuator at higher resolution by using a greater number of bits (16 bits, for example) of the digital signal. In this case, in a wavelength tunable interference filter, for example, the dimension of the gap can be precisely controlled to extract light of a target wavelength.
A drive voltage signal generation device capable of processing a digital signal having a greater number of bits is, however, more expensive. There is therefore a problem of an increase in manufacturing cost of the voltage controller.